1. Field of the Invention
The present invention relates generally to a speaker unit and particularly to a speaker unit including a diaphragm having a voice coil attached thereto.
2. Description of the Related Art
Conventional art of a diaphragm for a speaker used in a speaker unit is described for example in Japanese Patent Laying-Open No. 2003-264890. More specifically, Japanese Patent Laying-Open No. 2003-264890 proposes a diaphragm for a speaker, including a diaphragm, a voice coil provided at an annular, recessed fitting portion provided at a back surface of the diaphragm, and a circumferential holding ring provided to the diaphragm circumferentially, the diaphragm having a larger thickness at the annular, recessed fitting portion than at the circumference to prevent the voice coil from easily coming off.
Japanese Patent Laying-Open No. 2003-264890 provides the diaphragm for a speaker with an annular, recessed fitting portion and provides radially outwardly of the annular, recessed fitting portion a projection projecting at the back surface of the diaphragm. A voice coil is provided at the annular, recessed fitting portion and the voice coil has a lead connected thereto and extending over the projection and via the circumferential holding ring to an external terminal.
The lead that straddles the projection is bent and thus undergoes stress. When the speaker unit is driven for a long period of time with the lead undergoing stress, the lead suffers metal fatigue and is broken.